The sudden death of two people using Canada's busiest highway on a sunny weekend afternoon triggered response on social media to compare Highway 401 safety features along the Windsor to London corridor.

Two Windsor residents, Marc Lafontaine, 35, and his passenger, Alyssa Smulders, 13, were killed Saturday when the car they were travelling in was struck by a tractor trailer moving in the opposite direction.

The driver of the truck, Leszek Urbaniak, 57, of London was treated at the scene, some distance away from the wreckage, and then moved into an ambulance and taken to hospital with undisclosed injuries. Initially, Urbaniak was listed in stable condition, but by Sunday he had been release from hospital.

Chatham-Kent OPP Const. Janine Belanger said for some unknown reason, a westbound tractor trailer crossed a grass median and entered the eastbound lanes, just west of the Mull Road overpass, shortly before 2:30 p.m.

Once the OPP had closed the highway in both directions and all the vehicles between Kent Bridge and Communication roads had passed by the scene, Chatham-Kent firefighters had to return to the crash site to extricate the bodies of the deceased.

"The OPP Technical Traffic Collision Investigation team is on scene assisting with the investigation," Belanger said. "If there are any witnesses to this collision, please contact Chatham-Kent OPP at 519-352-1122," she added.

While the investigation into the collision continued, reaction to the news of the preventable deaths on social media caused people to wonder why the highway remains divided only by a bevelled grass strip through Chatham-Kent and Elgin County.

"Really sad to hear two people lost their lives just minding their own business, driving the highway," one person wrote.

"How many people have to die before MTO installs Armco barriers from Talbotville to Tilbury? Make it an election issue. Contact your MPP ," another person commented.